Technet, We use an X-ray flourescence scope to measure solder thickness and composition. Recently, we sent samples to a university to have the composition measured by Edacs (I probably spelled that wrong). In case I spelled that wrong and you don't know what I mean - Edacs composition measurements are a by-product of scanning electron microscopes. Anyway, the tin-lead percentages we got from Edacs were way different from the results we got on our X-ray. I'm thinking this might be because the Edacs measures an extremely small surface area whereas the X-ray measures a 5 to 10 mil diameter circle. Does anyone have any experience with SEM and/or Edacs in relation to solder composition? We would appreciate any info to confirm my theory or refute. Thanks, Dave Hall [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************